Photo-sensitive sheet drying apparatus

ABSTRACT

An improvement of a photo-sensitive sheet drying apparatus having upper and lower conveyor belts arranged lengthwise in the parallel relationship. The apparatus has means to drive these conveyor belts at equi-speed in one direction, thus assuring the smooth transportation of photo-sensitive sheets in the course of the drying operation without the curled end of the wet sheet catching when dried.

United States Pateni Miyata et al. Apr. 2, 1974 [54] PHOTO-SENSITIVESHEET DRYING 3,369,306 2/1968 Evans 34/162 APPARATUS 3,434,225 3 1969Knibiehly... 34/160 3,405,456 10/1968 Shepherd 34/155 lflvemorslTomlflkl y ShmJl Ramada; 3,328,895 7/1967 Krone et al. 34 68 ShigenobuWatanabe; Toshiko 3,199,213 8/1965 Milligan 01. a]. 34/13.8 Ogawa, allof Kanagawa-ken, Japan 3,071,866 1/1963 Mangus 34/73 n 1,560,579 11 1925Jones 1 34/155 Asslgneei FIlJl ShaShIn1 Fllm Kabushlkl Kalsha, 1,426,0958 1922 Parker 34/155 Ashlgarakaml-gun, Kanagawa-ken, J an FOREIGNPATENTS OR APPLICATIONS 742,858 2/1952 Germany 1. 34/155 [22] 1971288,139 6/1929 Great Britain 34/162 [21] App]. No.: 172,100

Primary Examiner-Meyer Perlin 30 Foreign Application priority mAssistant ExaminerPaul Devinsky Aug. 20, 1970 Japan 45-72923 [57]ABSTRACT [52] US. Cl 34/151, 34/155, 34/152 51 Int.C1. ..1F26b13/10A"mPmVePemofaphcto'senstvesheedrymgap' [58] Field 61 Search 34/155, 162,151, 152, Params havmg and belts ranged IengthWiSe in the parallelrelationship. The ap- 198/'165.271/45 paratus has means to drive theseconveyor belts at equi-speed in one direction, thus assuring the smoothf hoto-sensitive sheets in the course [56] References Citedtransportailon 0 p UNITED STATES PATENTS of the drying OIL-12110 withoutthe curled end of the wet sheet catching when dried. 3,681,853 8/1972Reid 34/151 3,440,944 4/1969 Endermann et a1. 34/155 8 Claims, 7 DrawingFigures PAIENIEDAPR 2 m4 3800.432

- sum 1 or 2 ezagg mm PATENIEB APR 2 74 SHEET 2 0F 2 PIC-3.5

1 PHOTO-SENSITIVE SHEET DRYINGHAPPARATUS This invention relates to anapparatus for drying wet photo-sensitive sheets, and more particularlyto a dryer of the type using a conveyor means against which the wetphoto-sensitive sheet is pushed by a stream of gas blowing onto thesheet to dry thesame.

The automatic transporting type photo-sensitive sheet drying apparatuswhich is commonly used comprises a roller conveyor. The photo-sensitivesheet tends to curl in the course of the drying operation because of thedifference in the thermal elongations of a relatively thick gelatinecoating on one surface of a film base sheet and a relatively thingelatine coating on the other surface of the film base, and when thecurled end of the photo-sensitive sheet is caught in the conveyor, itwill turn aside from the passageway, defined by the conveyor, andtherefore cannot be carried further.

The automatic transporting type dryer which is also commonly used,comprises two parallel belt conveyors between which the photosensitivesheet is closely gripped. This dryer will not allow the photo-sensitivesheet to curl, and therefore it can convey the photosensitive sheetwhich has a strong inclination to curl when dried. However, the wetphoto-sensitive sheet cannot be dried evenly, and the pattern of stripetraces of the belt remains on the photo-sensitive sheet after it hasbeen dried, thus deteriorating the appearance or image quality of thephoto-sensitive sheet.

A dryer of the type to which this invention relates, comprises upper andlower conveyors. The photosensitive sheet is pushed against one of theseconveyors by a stream of drying gas and is carried by said one conveyor.When the wet photo-sensitive sheet is dried, the fore and/or rear end ofthe sheet will curl increasingly until the curled end of the sheettouches the surface of the lower conveyor belt and is caught in theconveyor, thus preventing the sheet from further travelling or causingthe following sheet to reach and overtake the retarded sheet.

The object of this invention is to provide a photosensitive sheet dryingapparatus capable of smoothly transporting the photo-sensitive sheetwhich will tend to curl while it is subjected to the drying operation,and of drying the sheet without deteriorating the appearance or picturequality thereof.

This object has been attained by the drying apparatus according to thisinvention which comprises upper and lower conveyors moving at equi-speedin one direction and transporting the photo-sensitive sheet, whichexists between the upper and lower conveyors and is pushed against oneof these conveyors by a stream of drying gas blowing from a perforatedplate through the other conveyor.

The term conveyor used hereinafter, indicates a belt type conveyor, aroller type conveyor and other conveyors of any type.

This invention will be better understood from the following descriptionwhich is made with reference to the accompanying drawings in which:

FIG. 1 shows one embodiment of this invention having upper and lowerconveyor belts of a material capable of air passage;

FIG. 2 shows another embodiment having upper and lower conveyor beltsboth consisting of an arrangement of staggered rollers;

FIG. 3 depicts a different embodiment whose upper and lower conveyorsconsist of an air-passing belt and an arrangement of rollersrespectively;

FIG. 4 shows an embodiment similar to that shown in FIG. 3, but theupper conveyor thereof consists of an arrangement of staggered rollerswhereas the lower conveyor consists of an air-passing belt;

FIG. 5 is a plan view of a air-passing belt;

FIG. 6 is a plan view of an arrangement of staggered rollers; and

FIG. 7 shows an embodiment of this invention whose air-passing plate hasa number of air holes slanting with respect to the travelling directionof the conveyor.

Referring to FIG. 1, the upper and lower conveyors l1 and 12 of theapparatus each consists of an airpassing belt. These conveyors move atequi-speed in the same direction.

The photo-sensitive sheet 3 is pushed against the upper conveyor belt 7by a stream of drying gas passing through the lower conveyor belt 8. Thefore and rear ends of the photo-sensitive sheet 3 curl increasingly withthe progress of the drying operation until the curled ends of the sheet3 have touched the surface of the lower belt 12, travelling with theconveyors l1 and 12.

More specifically, the stream of air from a fan 4 is heated afterpassing through a heat source 5 and then the warm air stream blows fromnumerous air holes 6 through the lower conveyor belt 8, thus pushing thephoto-sensitive sheet 3 against the upper conveyor belt 11. Then, thephoto-sensitive sheet 3 can be carried by the upper belt conveyor 11. Inthe course of the drying operation the fore and rear ends of the sheetcurl increasingly until the ends of the sheet have been brought in closecontact with the lower conveyor belt 12 which travels at the same speedand in the same direction as the upper conveyor belt 11. Thus, thephoto-sensitive sheet will not be caught in the conveyor and it will besmoothly carried without being lowered in the quality of its appearanceor image.

In FIG. 2, the upper and lower conveyors 21 and 22 consist of anarrangement of numerous staggered rollers 13. A stream of air from a fan4 is heated by a heater 5, and then the warm air blows from numerous airholes 6 to pass through the lower conveyor 22 to the photo-sensitivesheet 3 which is pushed against the upper conveyor 21, and is carried bythe same. The fore and/or rear ends of the sheet will curl increasinglyin the course of drying until the curled end of the sheet touches on thesurface of the lower conveyor. This, however, will cause no troublebecause the lower conveyor 22 travels at the same speed and in the samedirection as the upper conveyor 21. Otherwise, the curled end of thesheet will be caught in the lower conveyor. As a result, the sheet willbe put aside from the passage, or it will be retarded and finally thefollowing sheet will reach and overtake the retarded sheet. As a matterof course, this will cause malfunction in the dryer. Advantageously, thedegree of curling will be suppressed somewhat by the upward stream ofair to cause the curled end of the sheet to rise.

In FIG. 3 the upper conveyor 31 consists of an airpassing belt whereasthe lower conveyor 32 consists of an arrangement of staggered rollers.In FIG. 4 the upper conveyor 41 consists of an arrangement of staggeredrollers whereas the lower conveyor 42 consists of an air-passing belt.In these embodiments, similar to others shown in FIGS. 1 and 2, a streamof warm air passes through the lower conveyor belt and dries the wetphoto-sensitive sheet while pushing the same against the upper conveyorbelt.

The air-passing belt suitable for use in the apparatus of this inventionconsists of a net of a cellulose or a synthetic resin as shown in FIG.5. Alternatively a plurality of strings stretched in the same directionas the travelling direction of the photo-sensitive sheet can be used.The belt can be made ofa porous substance which must be thermostable atthe temperature of 1 C.

The arrangement of numerous staggered rollers is shown in FIG. 6. Thestaggering arrangement prevents the curled end of the photo-sensitivesheet from protruding from the space between the adjacent rods to whichthe rollers are fixed.

The use of air holes slanting with respect to the travelling directionof the photo-sensitive sheet as shown in FIG. 7 assures a smooth streamof air along the underface of the sheet without fluttering the sheet,and therefore such slant holes are useful in positioning the sheet inplace. In other words, the slant holes will not cause the distortion inthe stream of air which would take place in striking against the sheetin the normal direction and flowing along the surface of the sheet inthe opposite directions.

What is claimed is:

l. A photo-sensitive sheet drying apparatus comprising:

a. a first conveyor means which is permeable to a stream of gas;

b. a second conveyor means vertically spaced apart from said firstconveyor means, said first and second conveyor means being lengthwiseparallel to each other;

c. means for simultaneously moving said first and second conveyor meansin the same direction and at equal speeds, said first and secondconveyor means being capable of guiding between them a photosensitivesheet; and

d. means for supplying and directing a stream of gas through said firstconveyor means towards said second conveyor means, said first and secondconveyor means being spaced such as to enable only the ends of the sheetto touch said first conveyor means while an intermediate portion of thesheet contacts the second conveyor means when there has been sufficientdrying to cause curling of the sheet.

2. A photo-sensitive sheet drying apparatus according to claim 1 whereinsaid first conveyor means comprises a reticulate belt.

3. A photo-sensitive sheet drying apparatus according to claim 1 whereinboth of said conveyor means comprise an arrangement of staggeredrollers.

4. An apparatus according to claim 1 wherein one of said conveyor meanscomprises a reticulate belt whereas the other conveyor means comprisesan arrangement of staggered rollers.

5. An apparatus according to claim 1 wherein said means for directing astream of gas comprises a perforated plate having numerous air holesnormal to the travelling direction of said conveyor means.

6. An apparatus according to claim 1 wherein said means for directing astream of gas comprises a perforated plate having numerous holesslanting in the travelling direction of said conveyor means.

7. An apparatus according to claim 1 wherein said stream of gas issufficient to force a wet, photosensitive sheet against said secondconveyor means.

8. A photo-sensitive sheet drying apparatus according to claim 1 whereinat least said second conveyor means comprises a crosswise staggeredarrangement of disc roller elements.

1. A photo-sensitive sheet drying apparatus comprising: a. a firstconveyor means which is permeable to a stream of gas; b. a secondconveyor means vertically spaced apart from said first conveyor means,said first and second conveyor means being lengthwise parallel to eachother; c. means for simultaneously moving said first and second conveyormeans in the same direction and at equal speeds, said first and secondconveyor means being capable of guiding between them a photo-sensitivesheet; and d. means for supplying and directing a stream of gas throughsaid first conveyor means towards said second conveyor means, said firstand second conveyor means being spaced such as to enable only the endsof the sheet to touch said first conveyor means while an intermediateportion of the sheet contacts the second conveyor means when there hasbeen sufficient drying to cause curling of the sheet.
 2. Aphoto-sensitive sheet drying apparatus according to claim 1 wherein saidfirst conveyor means comprises a reticulate belt.
 3. A photo-sensitivesheet drying apparatus according to claim 1 wherein both of saidconveyor means comprise an arrangement of staggered rollers.
 4. Anapparatus according to claim 1 wherein one of said conveyor meanscomprises a reticulate belt whereas the other conveyor means comprisesan arrangement of staggered rollers.
 5. An apparatus according to claim1 wherein said means for directing a stream of gas comprises aperforated plate having numerous air holes normal to the travellingdirection of said conveyor means.
 6. An apparatus according to claim 1wherein said means for directing a stream of gas comprises a perforatedplate having numerous holes slanting in the travelling direction of saidconveyor means.
 7. An apparatus according to claim 1 wherein said streamof gas is sufficient to force a wet, photo-sensitive sheet against saidsecond conveyor means.
 8. A photo-sensitive sheet drying apparatusaccording to claim 1 wherein at least said second conveyor meanscomprises a crosswise staggered arrangement of disc roller elements.